CLEMSON, S.C. — Clemson got a last-minute boost Wednesday in defensive back Mackensie Alexander and offensive lineman Tyrone Crowder Jr. to bolster what had been a fading class of recruits.

Alexander was rated the fourth-best college prospect by ESPN and was the highest-rated player to sign with the Tigers since defensive end Da’Quan Bowers, the No. 1 overall prospect that year, joined Clemson in 2008.

Alexander, of Immokalee, Fla., was part of a late signing-day charge by Clemson and coach Dabo Swinney that also included Crowder and defensive backs Adrian Baker and Ryan Carter, a Grayson High School player talked up last summer by defensive end Robert Nkemdiche, his teammate and this year’s No. 1 player.

Nkemdiche was a Clemson commitment back in July when he said he’d also like the Tigers to sign Carter — and began a debate about how far a school should go to land one of the nation’s best players. Turns out, Clemson liked what it saw from Carter and gladly brought him in, Swinney said.

The Tigers weren’t so fortunate with some of their other high-profile commitments. Nkemdiche eventually decommitted and signed with Ole Miss. Top defensive line prospects Elijah Daniel, also committed to the Tigers, backed off and signed with Auburn. Wide receiver Demarcus Robinson pledged to Clemson, but he also changed his mind and enrolled with Florida.

“We had a few spots open, a little bit of attrition,” he said.

Swinney is excited about players the Tigers added, particularly on defense. They literally crisscrossed the United States to offset the loss of Nkemdiche and Daniel along the defensive line with Ebenezer Ogundeko from Brooklyn, N.Y., and Scott Pagano from Honolulu, Hawaii.

Swinney wasn’t worried about the players who didn’t pick the Tigers, only those who did.

“That mentality is like waking up at Chirstmas and getting a lot of nice presents and going, ‘Oh, this is all I got?’” he said.

Swinney said what the Tigers got was a top-15 group of players to add to an 11-2 squad from this past season. “They could’ve gone away from Southern Cal to Florida and anywhere in between,” Swinney said. “These kids had offers, but they chose Clemson.”

Still, recruiting coordinator and receivers coach Jeff Scott couldn’t help but think about how close the Tigers came to getting the biggest prize of all in Nkemdiche, who chose to join his brother with the Rebels.

Nkemdiche’s mother, Beverly, is a politician in Nigeria who was not pleased with son Robert’s pick of Clemson last year. The Tiger coaches were not able to make any inroads and Scott said they’d never accept a player whose family was not behind them joining the Tigers.

Scott, though, says Clemson will keep on pitching the game’s best. “I always like fishing in the pond with the chance to get the big fish,” he said.

ESPN recruiting analyst Tom Luginbill said Clemson made some large splashes with its pledges last year from Nkemdiche, Robinson and Daniel. But the trick is to keep them in the fold. “It’s a very long process,” Luginbill said. “The chum is always in the water and the sharks are always circling.”

Alexander, at 5-foot-11, had four interceptions, two forced fumbles and a fumble recovery as his Immokalee High team reached its championship game. Crowder, of Richmond Senior High in Rockingham, N.C., is 6-2 and 325 pounds. He played in two all-star games following his senior season and Swinney expects he’ll be a foundation of Clemson’s line for several seasons.

Swinney said Clemson was able to rebound well from the commitments that didn’t stick, evidenced by the quality players they signed. Expect that to continue, he said.

“We’ve raised the bar and that’s a good thing. We’re going to continue to do that,” he said. “We’re beyond the point where people should be surprised when Clemson signs a good player or a good class.”

CLEMSON SIGNEES

CLEMSON, S.C. — Clemson’s group of 23 football signees with position, height, weight, previous school and hometown: